Morphological evidence for supporting cell to hair cell conversion in the mammalian utricular macula

摘要: Abstract The possible origin of the immature hair cells that appear in utricular maculae guinea pigs following gentamicin-induced cell death was investigated. Guinea were continuously infused with bromodeoxyuridine, to label proliferating and their progeny, for 2 weeks after inducing damage inner ear on one side gentamicin. opposite each animal served as control. Serial sections cut through entire both ears number labelled epithelium underlying connective tissue counted. Label present sensory utricles from drug exposed but not controls. nuclei also ears. Some at level normally occupied by cells, most supporting nuclei. However, total small; maximum 12 animal. treated significantly greater than untreated ear. This confirms proliferation is stimulated mature mammalian macula loss, extent which it occurs appears be insufficient explain recovery numbers observed. Detailed thin section studies gentamicin-treated animals over a prolonged post-treatment period performed. In had suffered damage, there which, like unlike resting basement membrane, possessed apical ends organized bundles microvilli similar stereocilia. Other more obvious stereocilia remained contact membrane via small foot process. still other where stereociliary bundle almost appearance, process extending towards quite contact, suggesting just detached. All these contacted nerve endings specialization membranes apparent site cell-neurone contact. morphological characteristics are consistent phenotypic conversion into this may account some production vestibular epithelia death.